by Chinh Le, LeWiz Communications
Designers of enterprise networks and networking equipment face continuing price/performance challenges. Users are constantly requesting more bandwidth for larger and more demanding applications. However, the cost of providing that additional bandwidth is often surprisingly high. For example, Gigabit Ethernet ports and connections have currently reached commodity prices (less than $50), whereas 10-Gigabit devices, although available, cost much more. Multi-port gigabit Ethernet cards, now provided in compact forms, offer an intermediate solution, improving performance significantly while still keeping costs under control.

Obviously, bigger pipes provide more throughput. The new 10-Gigabit devices thus provide the best performance in Ethernet networks. However, they currently cost 100 times what Gigabit devices cost. So, at the moment, their use is generally restricted to special applications, such as aggregators and other combined pipes.

An added complication is that cost is not the only factor. Gigabit technology is mature and reliable. Software such as drivers and iSCSI storage application stacks are readily available for GigE hardware. GigE standards are also well defined, making the devices more interoperable, especially in a heterogeneous network environment. In such situations, servers and clients are typically running a mixture of operating systems such as Windows, Linux, Solaris, and UNIX. The different platforms typically also utilize different processors such as Xeon, Opteron, or SPARC. Time-proven Gigabit Ethernet devices are much easier to get up and running than the newer and less proven 10-Gigabit devices.

Multiport gigabit NICs can provide an intermediate solution. One can produce a big pipe by bonding several GigE ports together. For example, one can create a 4 Gbps per second port by bonding 4 Gigabit ports together. When used for storage backup, such a configuration provides performance equivalent to that of a typical 10-Gig NIC at a fraction of the cost. And note that the technology is proven and widely supported. One can also easily use multiple ports to provide failover fault-tolerant capability using dual or quad redundancy. The extra ports can be switched over different networks, ensuring systems will be up and running even during an outage of the primary networks.

An example of multi-Gigabit NIC is LeWiz Communications‚ Talon3008 card with four independent Gigabit ports. This low-power PCI Express card even offers TCP/IP assist functions to reduce CPU workload. Built in a PCI-E low-profile form factor, the board is plug-and-play for most systems. It readily supports Windows2000/2003 Server, Solaris10/Express, Linux2.4/2.6, and RedHat or SuSE Enterprise operating systems. The hardware has been tested on both AMD Opteron and Intel Xeon platforms in both 32 and 64 bit configurations.

Current price/performance tradeoffs mean that 10-Gig Ethernet is practical only for a few large pipes in most networks. One way to avoid the high price of 10-Gig ports is to aggregate gigabit ports instead. Multi-port NICs currently provide performance comparable to 10-Gigabit adapters at a small fraction of the price. Such NICs utilize proven technology and are simple to install and operate.